Alloy



Patented Nov. 12, 1935 f 2,020,949

V Y: 1 TA J PATENT 1 OFFICE Y ALLOY' V Robert H. Leach, Fairfield, Conn assignor to Handy & Harman, New York, N. Y., a. corpora.- tion of New York No Drawing. Application November 6,1934,

I Serial No. 751,710 i \v 7Claims. (01.75-1) 7 p This invention relates to alloys and is conreadily oxidized and at present is somewhat excerned more particularly with an alloy containpensive. ing silver, copper, andberyllium. The new alloy. Examples of the new alloy which are suitable is capable of being given great hardness by suitfor commercial purposes are as follows, the

5 able heat treatment and because of that and its analyses being approximate in each case: 6

Example No. 1

for electrode tips, contact points, etc. silver Per g The new alloy resembles that described and Co I, 93 8 1o claimed in my. Patent No. 1,928,429, September B fi I 7 -10 26, 1933, inthat itcontains the same ingredients, 1 4 but it differs from the alloy of the patent in the Example No. 2 respects that it contains less silverand more Y Y Per cent copper, and has different physical properties. By Silver. e I a 20 reason of the smaller proportion of silver, the Copper 78 15 new alloy can be made at a lower cost than the Beryllium k 2 pa ent'ed alloy 'Also, it can be made considerably harder than the patented alloy by proper f Example 9 3 mt heat treatment The new alloy has a somewhat sflver e 3 r lower electrical conductivitythan the alloy of the Co 7f 68 20 patent, and thus the advantages of lower cost and g- 3 1 75 anced by the reduction in conductivity. But the The alloy of Example No. l'may be considered conductivity of the new alloy is satisfactory for as representative of a class, the members of which 25 some purposes, and in those instances, its relacontain silver ranging from 5% to 20%, copper 25 tively low cost and its capacity for being given ranging from 78% to 94%, and beryllium ranging great hardness make its use highly desirable. from Y 1% to 2.5%. Alloys in this class may be The new alloy contains silver ranging from 5% given a hardness which ranges from 100th 112 to 50%, beryllium ranging from 0.5% to '.5%, on the Rockwell 3 scale, depending on the comand the remainder copper, Within these ranges: position and the heat treatment, and their elec- 30 an increase in the amount of silver increases the trical conductivity varies from 30% to of electrical conductivity of the alloy while an inthat of pure copper. v crease in the amount of beryllium inoreases'the The alloy of Example No. 2 may be considered capacity.of the alloy to be hardened by proper to'be representative of a' class, the members of 35 treatment. Ordinarily, beryllium is present in an which contain silver ranging from20% to 40%, 35 amountnot less than 315% and preferably the copper ranging, from 58% to 78%, and beryllium amount does not exceed about 1.75% or 2%, since ranging from 0.5% to 2.5%. Such alloys have a too-great a proportion of the beryllium may make Rockwell "Bf hardness of 68 to 112 and a conduc- I the alloy somewhat brittle. Where the use of the tivity from 35% to 50% of that-of pure copper,

40 alloy is such that extreme hardness isdesired and dependingupon the percentages of the various-10 a tendency toward brittleness is not objectionable, ingredients and of the heat treatment to which the amount of beryllium employed may approach the specific alloy is subjected. The alloy of Exthe upper limit. ample No.-3 is another member of this class.

In making the new alloy, the beryllium is-pref-I In addition to the classes above described, 'exv erably employed in theeform of a master alloy ampl'es of the new alloy may fall into a third 45 containing silver or copper and about 10% to 12% class, the members of which contain silver rangv or 13% beryllium. This master alloy is then ingrrom 40% to%, copper-ranging from 47.5% combined with suitable amounts of silver and to 58%, and beryllium ranging from 0.5% to2.5%.

copper'to produce the final alloy. The use of The members of class have aRockwell 3* 50 the master alloy is desirable since beryllium is hardness varying-from 68 to 'andaconductiv- 50 pending upon the composition and heat treatment.

. The method of hardening the new alloy is simi- 5 lar to that described in my patent above mentioned. The alloy is first annealed for a sub-' stantial period of time and then instantly quenched. It is then heated for a further period of time at a lower temperature, aigreat increase in hardness resulting from the second heating. While the heating in both instances; is a function of both time and temperature, for many purposes, it is satisfactory to carry out the preliminary annealing by heating the alloy for a period of about two hours at a temperature ranging from about 1375? F. to 1400 F. subjecting the alloy to' such temperatures for the time mentioned appears to result in substantially complete solid solution. Following the quenching, further heating of the alloy gives the precipitation hardening efiect. For some of the new alloys, I have found that the desired hardening may be obtained by heating for a period of about two hours at a temperature ranging from about 625 F. to about 650 F., although heating for a longer period may be required to obtain complete precipitation. Temperatures as high as 675 F. do not provide Y the same degree of hardening as the lower temperatures, but temperatures lower than 625 F. may be used, provided the heating is carried on. for a longer time.

r The heat treatment described imparts great hardness to the alloy and the degree of hardness depends on the amount of beryllium present. For the same amount of beryllium and with heat treatment under the same conditions, the new alloy has a greater hardnessthan that of the patent.

WhatI claim is: V

1.- An alloy consisting of silver in an amount ranging from about 5% to an amountiexceeding 40% and substantially less than beryllium in an amount ranging from about 0.5% to about 2.5%, and the remainder copper.

2. An alloy which consistsof silver ranging from about 5% to about 20%, copper ranging from about 78% to about 94%, and beryllium ranging from about 1% to about 2.5%.

3. An alloy which consists oi silver ranging from about 20% to about 40%, copper ranging from about 58% to about 78%, and beryllium ranging from about 0.5% to about 2.5%.

4. An alloy which consists of silver ranging from about 40% to an amount substantially less than 50%, copper ranging from about 47.5% to about 58%, and beryllium ranging from about 25 0.5% to about 2.5%.

5. An alloywhich consist of about 5% silver, about 93.8% copper, and about 1.2% beryllium.

6. An alloy which consists of about 20% silver, about 78% copper, and about 2% berylliumf 7. An alloy which consists of about 30% silver, about 68.25% copper, and about 1.75% beryllium.

ROBERT H. LEACH. 

